JP2011095746A - Photoresist composition and method of manufacturing display substrate using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoresist composition and a method of manufacturing a display substrate using the same. <P>SOLUTION: The photoresist composition includes an alkali-soluble resin, a dissolution inhibitor including a quinone diazide compound, a first additive including a benzene compound, a second additive including an acrylic copolymer, and an organic solvent. Accordingly, heat resistance of a photoresist pattern may be improved, and the photoresist pattern may be readily stripped. As a result, crack is prevented from occurring in the photoresist pattern. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photoresist composition and a method for producing a display substrate using the same. In more detail, it is related with the photoresist composition used for manufacture of the display substrate for display apparatuses, and the manufacturing method of a display substrate using the same.

  Generally, a liquid crystal display (LCD) is disposed between a display substrate on which a thin film transistor for driving each pixel is formed, a counter substrate facing the display substrate, and the display substrate and the counter substrate. A liquid crystal layer. The display substrate has a structure in which a gate pattern, a semiconductor pattern, a source pattern, and a pixel electrode are stacked on a base substrate. Each of the gate pattern, the semiconductor pattern, the source pattern, and the pixel electrode may be formed by patterning a thin film through a photolithography process.

  Recently, a process using two existing masks is a process of patterning two different thin films using only one mask. Specifically, photoresist patterns having different thicknesses are formed on the first thin film and the second thin film sequentially stacked, and the first and second thin films are patterned using the photoresist pattern as a mask. Subsequently, the second thin film can be patterned using a residual pattern formed by removing a part of the photoresist pattern as a mask. This can reduce production costs by reducing the use of expensive masks.

  However, in the process of patterning the second thin film using the residual pattern as a mask, the residual pattern is easily damaged or reflowed by the etchant of the second thin film. As a result, the second thin film is etched more relatively than the first thin film, and the first thin film pattern has a relatively protruding shape as compared to the second thin film pattern. When the second thin film is a source metal layer and the first thin film is a silicon layer, the first thin film pattern is displayed from the second thin film pattern in spite of the second thin film pattern actually acting as an electrode or a signal wiring. Occupies a large area on the substrate. This reduces the aperture ratio of the display substrate.

  Accordingly, in order to form a fine photoresist pattern, high heat resistance of the photoresist pattern is required. Also, cracks should not be generated on the surface of the photoresist pattern by a low temperature or chemical substance, and the photoresist pattern should be easily removed by a stripper. However, if the heat resistance of the photoresist pattern is strengthened, it becomes difficult to remove the photoresist pattern, and if the processing temperature is lowered to facilitate the removal of the photoresist pattern, there is a problem such as generation of cracks. There is a growing demand for the development of photoresist compositions that solve this.

  This invention is made | formed in view of the said subject, and is providing the photoresist composition which improves the reliability of a photoresist pattern.

  Another object of the present invention is to provide a method for manufacturing a display substrate using a photoresist composition.

  A photoresist composition according to an embodiment of the present invention is represented by an alkali-soluble resin, a dissolution inhibitor containing a quinonediazide compound, a first additive containing a benzole compound represented by the following chemical formula (1), and a chemical formula (2) below. A second additive containing an acrylic copolymer and an organic solvent are included.

  In the chemical formula (1), R1, R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkylhydroxy group having 1 to 10 carbon atoms, R1, At least one of R2 and R3 represents a hydroxy group, and in the chemical formula (2), R4, R5 and R6 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R7 represents a hydrogen atom. Valent substituted or unsubstituted hydrocarbon having 1 to 6 carbon atoms, R8 represents benzyl group or phenyl group, m, n and k are each independently a natural number of 1 to 99, and m + n + k = 100.

  The alkali-soluble resin includes a classified novolac resin.

  The classified novolac resin has a glass transition point of 120 ° C. or higher and 150 ° C. or lower.

  The classified novolac resin has a weight average molecular weight of 20000 g / mol or more and 30000 g / mol or less.

  The photoresist composition comprises 10% to 25% by weight of the alkali-soluble resin, 1% to 10% by weight of the dissolution inhibitor, and 0.1% to 10% by weight of the first additive. 0.1 wt% or more and 10 wt% or less of the second additive and the organic solvent.

  In a method for manufacturing a display substrate according to an embodiment of the present invention, a gate pattern including a gate line and a gate electrode is formed on a base substrate. A gate insulating layer, a semiconductor layer, an ohmic contact layer, and a source metal layer are formed on the base substrate including the gate pattern. On the base substrate including the source metal layer, an alkali-soluble resin, a dissolution inhibitor including a quinonediazide compound, a first additive including a benzole compound represented by the following chemical formula (1), and an acrylic copolymer represented by the following chemical formula (2) A photoresist pattern is formed using a photoresist composition containing a second additive containing a polymer and an organic solvent. A source pattern including a data line, a source electrode and a drain electrode using the photoresist pattern, a line pattern formed under the data line, and an active pattern including a channel portion under the source electrode and the drain electrode. Form. A pixel electrode electrically connected to the drain electrode is formed on the base substrate including the source pattern, the line pattern, and the active pattern.

  The photoresist pattern includes a first thickness portion formed at a first thickness on a region where the source pattern is formed, and a separation region between the source electrode and the drain electrode. A second thickness portion formed with a second thickness smaller than the thickness is included.

  The photoresist pattern may be heat-treated at 140 ° C. or higher and 150 ° C. or lower before the step of forming the line pattern. The photoresist pattern may have substantially the same shape before the heat treatment and after the heat treatment.

  ADVANTAGE OF THE INVENTION According to this invention, while improving the heat resistance of a photoresist composition, the photoresist composition which strips a photoresist pattern easily and prevents that a crack arises in a photoresist pattern, and a display substrate using the same The manufacturing method of can be provided.

It is sectional drawing which shows the display substrate which concerns on embodiment of this invention. It is sectional drawing which shows the display substrate which concerns on embodiment of this invention. It is sectional drawing which shows the manufacturing method of the display substrate shown in FIG. It is sectional drawing which shows the manufacturing method of the display substrate shown in FIG. It is sectional drawing which shows the manufacturing method of the display substrate shown in FIG. It is sectional drawing which shows the display substrate which concerns on other embodiment of this invention. It is sectional drawing which shows the display substrate which concerns on other embodiment of this invention.

  The present invention can be modified in various ways and can have various forms, which will be described in detail in the present specification by exemplifying drawings in the embodiments. However, this should not be construed as limiting the invention to the particular forms disclosed, but should be understood to include all modifications, equivalents, or alternatives that fall within the spirit and scope of the invention. In the drawings, the same reference numerals are used for the same components. Terms such as first and second are used to describe various components, but these components should not be limited by terms. The terminology is used to distinguish one component from another. The terminology used herein is for the purpose of describing embodiments only and is not intended to be limiting of the invention. The singular form includes the plural form unless the context clearly dictates otherwise. In this specification, terms such as “including” or “having” are intended to designate the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification. It should be understood that the existence or addition of one or more other features, numbers, steps, operations, components, parts, combinations thereof, etc. is not excluded in advance. It is.

  Unless otherwise defined, all terms used in the specification, including technical or scientific terms, are the same as those generally understood by those having ordinary knowledge in the technical field to which the present invention belongs. It has a meaning. It should be understood that the same terms as defined in commonly used dictionaries are consistent with the meaning they have in the context of the related art, and are interpreted as ideal or formal meanings unless explicitly defined herein. should not be done.

  In the accompanying drawings, the size of a substrate, layer (film), or pattern is shown enlarged from the actual size for the sake of clarity of the present invention. In the present invention, each layer (film), pattern or structure is referred to as being formed “on” or “upper”, “under” or “lower” of the substrate, each layer (film) or pattern. In some cases, each layer (film), pattern or structure is directly formed on the substrate, each layer (film) or pattern, meaning that it is located under the pattern, other layers (films), Other patterns or other structures are additionally formed on the substrate.

Photoresist Composition A photoresist composition according to an embodiment of the present invention includes a) an alkali-soluble resin, b) a dissolution inhibitor, c) a first additive, d) a second additive, and e) an organic solvent.

(A) Alkali-soluble resin Alkali-soluble resin contains classification type novolac-type resin (fractionated novolac resin). The classification type novolac resin is defined as a high molecular region resin and a low molecular region resin obtained by separating the synthesized resin and cutting the middle molecular region in the molecular weight distribution of the resin. It is referred to as “classified novolac resin”.

  The alkali-soluble resin may be obtained by addition-condensation reaction of a phenol compound and an aldehyde compound or a ketone compound. The compound subjected to the addition-condensation reaction can be subjected to a fractionation treatment and cut to remove the high molecular region and the low molecular region to obtain a classified novolak resin. For example, the classification method is a method of selectively washing an alkali-soluble resin using a solvent or a combination of solvents in which the alkali-soluble resin can be partially dissolved, a method of dissolving and precipitating the alkali-soluble resin in a solvent, a solvent For example, a method of precipitating from a non-solvent that can be mixed with a solvent, a method of precipitating from a pre-scale size exclusion chromatography that can obtain a desired fractional molecular weight by dilution, and the like are used.

  Specific examples of the phenolic compound include phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol (2). , 5-xylenol), 3,5-xylenol (3,5-xylenol), 3,4-xylenol (3,4-xylenol), 2,3,4-trimethylphenol (2,3,4-trimethylphenol), 4-t-butylphenol (4-t-butylphenol), 2-t-butylphenol (2-t-butylphenol), 3-t-butylphenol (3-t-butylphenol), 3-ethylphenol (3-ethylphenol), 2 -Ethylfe 2-ethylphenol, 4-ethylphenol, 3,3-methyl-6-t-butylphenol (3-methyl-6-t-butylphenol), 4-methyl-2-t -Butylphenol (4-methyl-2-t-butylphenol), 2-naphthol (1,2-naphthol), 1,3-dihydroxynaphthalene (1,3-dihydroxynaphthalene), 1,7-dihydroxynaphthalene Alternatively, 1,5-dihydroxynaphthalene (1,5-dihydroxynaphthalene) and the like can be given. These may be used alone or in combination.

  Examples of aldehyde-based compounds include formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, phenylaldehyde, and phenylaldehyde. , -Phenylpropionaldehyde, ortho-hydroxybenzaldehyde (salicylaldehyde), m-hydroxy Cybenzaldehyde (meta-hydroxybenzaldehyde), p-hydroxybenzaldehyde (para-hydroxybenzaldehyde), glutaraldehyde (glyoxal), ortho-methylbenzaldehyde (ortho-methylbenzaldehyde) Can be mentioned. These may be used alone or in combination.

  Examples of the ketone compound include acetone, methylethylketone, diethylketone, methylphenylketone (acetophenone), diphenylketone, and the like. These may be used alone or in combination.

  The addition-condensation reaction between the phenolic compound and the aldehyde compound or ketone compound is performed in the presence of an acid catalyst. For example, the addition-condensation reaction may be performed at a temperature of about 60 ° C. to about 250 ° C. for about 2 hours to about 30 hours. Examples of the acid catalyst include oxalic acid (formic acid), formic acid (formic acid), trichloroacetic acid (trichloroacetic acid), organic acid including p-toluenesulfonic acid (para-toluenesulfonic acid), hydrochloric acid (hydrochloric acid), and the like. Divalent metal salts including sulfuric acid, perchloric acid, inorganic acid including phosphoric acid, zinc acid salt, magnesium acid salt, etc. Etc. You may mix and use these acid catalysts.

  When the weight average molecular weight converted to polystyrene of the classified novolak resin is less than about 20000 g / mol, the classified novolak resin is easily dissolved in the alkaline developer and lost. When the weight average molecular weight of the classified novolak resin exceeds about 30,000 g / mol, the difference in solubility in the alkaline developer between the exposed portion and the non-exposed portion of the photoresist composition is small, and a clear photoresist pattern can be formed. Have difficulty. Accordingly, it is desirable that the classified novolak resin has a weight average molecular weight of about 20000 g / mol or more and 30000 g / mol or less. Desirably, the weight average molecular weight is about 21000 g / mol or more and 29000 g / mol or less, and more desirably 2500 g / mol or more and 27500 g / mol or less. The classified novolac resin may have a narrow polydispersity index of 3 or less, desirably 2.5 or less, more desirably 2 or less.

  The classified novolac resin may have a glass transition temperature (Tg) of about 120 ° C. or more and about 150 ° C. or less. Accordingly, the photoresist pattern manufactured using the photoresist composition according to the embodiment of the present invention is not modified even at a temperature of about 120 ° C. or more and about 140 ° C. or less, which is a general heat treatment step of the photoresist pattern. Accordingly, according to an embodiment of the present invention, for example, a photoresist pattern manufactured using a photoresist composition at a high temperature of about 150 ° C. or higher may ensure high heat resistance of a photoresist pattern that is not modified by heat. .

  When the classified novolac resin is less than about 10% by weight based on the total weight of the photoresist composition, the heat resistance of the photoresist pattern is low, and the shape of the photoresist pattern cannot be maintained in the heat treatment process and easily collapses. Sometimes. Further, when the amount of novolak resin exceeds about 25% by weight, it is difficult to remove the photoresist pattern, and cracks may easily occur in the photoresist pattern. Therefore, the classified novolak resin is preferably about 10% by weight to about 25% by weight, more preferably 12% by weight to 23% by weight, and further preferably 15% by weight to 20% by weight of the total weight of the photoresist composition. % Or less.

  The alkali-soluble resin may contain different types of classified novolac resins. As an example, each classified novolac resin may be a resin obtained by classifying a phenol mixture obtained by mixing metacresol and paracresol in a weight ratio of 40:60 or more and 60:40 or less with formaldehyde and then classifying the mixture. Good. As another embodiment of the present invention, for example, the alkali-soluble resin may be obtained by reacting a phenol mixture obtained by mixing metacresol and paracresol in a weight ratio of about 60:40 with formaldehyde, and then classifying the resulting mixture. A weight average molecular weight of about 20000 g / mol obtained by reacting a phenol mixture prepared by mixing 20000 g / mol of a first classified novolak resin with metacresol and paracresol in a weight ratio of about 50:50 with formaldehyde. The second classified novolac resin may be included.

(B) Dissolution inhibitor The dissolution inhibitor contains a quinonediazide compound. Specifically, the quinonediazide-based compound is also referred to as a quinone diazide sulfonic acid ester compound or diazonaphthoquinone (DNQ). The quinonediazide sulfonic acid ester compound may be obtained by reacting a phenolic compound having a hydroxy group (also called a backbone) with a quinonediazide sulfonic acid halogen compound.

  Specific examples of the phenolic compound having a hydroxy group include 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,4,3′-tetrahydroxybenzophenone, 2, 3,4,4′-tetrahydroxybenzophenone, tri (p-hydroxyphenyl) methane, 1,1,1-tri (p-hydroxyphenyl) ethane, 4,4 ′-[1- [4- [1- [ 4-hydroxyphenyl] -1-methylethyl] phenyl] ethylidene] diphenol and the like. These may be used alone or in combination.

  Specific examples of the quinonediazidesulfonic acid halogen compound include 1,2-naphthoquinonediazide-5-sulfonic acid chloride, 1,2-naphthoquinonediazide-4-sulfonic acid chloride, and 1,2-benzoquinonediazide-4-sulfonic acid. Examples include chloride and o-quinonediazidesulfonyl chloride. These may be used alone or in combination.

  For example, a quinonediazide compound is obtained by reacting 2,3,4-trihydroxybenzophenone with o-quinonediazidesulfonyl chloride in the presence of a base containing triethylamine and the like and then separating it through post-treatment. Also good. The molar ratio of phenolic compound to quinonediazide sulfonic acid halogen compound is selected so that the ratio of DNQ to backbone forms a quinonediazide compound of 1: 1 or less based on the number of hydroxyl groups in the backbone. For example, 2,3,4-trihydroxybenzophenone may react and condense with o-quinonediazide sulfonyl chloride in a molar ratio of 1: 1, 1: 2, 1: 3 or an average combination thereof. In one example of post-treatment, the reaction may be mixed with water to precipitate the desired compound, filtered and dried to give the product on a powder. Alternatively, the reaction product may be treated with a resist solvent containing 2-heptanone, washed with water, phase-separated, and the solvent may be removed by distillation or equilibrium flash distillation to obtain the product in a solution in the resist solvent. . Equilibrium flash distillation refers to a type of continuous distillation in which a portion of a liquid mixture is distilled, and the generated vapor is sufficiently brought into contact with a liquid to form an equilibrium when the equilibrium is formed.

  When the dissolution inhibitor is less than about 1% by weight based on the total weight of the photoresist composition, the dissolution inhibitor may not be able to prevent the classified novolak resin in the non-exposed area from dissolving in the alkaline developer. When the dissolution inhibitor exceeds about 10% by weight, the classified novolac resin in the exposed area may not be dissolved in the alkaline developer. Accordingly, it is desirable that the dissolution inhibitor is about 1 wt% or more and about 10 wt% or less of the total weight of the photoresist composition.

(c) 1st additive The 1st additive contains the benzoles compound shown by following Chemical formula (1).

  In the chemical formula (1), R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkylhydroxy group having 1 to 10 carbon atoms, and R1, R2, and At least one of R3 represents a hydroxy group. The alkyl group may be linear or branched. For example, an alkyl group is methyl, ethyl, n-propyl, isopropyl, 1-butyl or 2-butyl, isobutyl, t-butyl, 1-pentyl, 2-pentyl or 3-pentyl, 1,1- or 2,2- Dimethylpropyl, 2-methylbutyl, 3-methylbutyl, 1-hexyl, 2-hexyl, 3-hexyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl or 3,3-dimethylbutyl, 1,2-dimethylbutyl 1,3-dimethylbutyl, 2,3-dimethylbutyl, 2-methylbutyl, 3-methylbutyl, n-octyl, 3-octyl, 1,1,3,3-tetramethylbutyl, n-decyl, cyclopentyl, 1 -Methyl cycllopentyl, cycllohexyl, 2-methoxyethyl, 2-exitoxyethyl, 2-methoxypropyl, Such as the Exhibition Toshi propyl and the like. You may mix and use these. Further, the alkylhydroxy group may be linear or branched. For example, the alkylhydroxy group is 2-hydroxyethyl, 2-hydroxypropyl, 2,3-dihydroxypropyl, 2-hydroxybutyl, 4-hydroxybutyl, 2,3-dihydroxybutyl, 2-hydroxypentyl, 2-hydroxyhexyl. , Hydroxycyclohexyl, methylhydroxycyclohexyl, 2,3- or 2,4-dihydroxymethyl, hydroxymethylcyclohexyl, inocityl, 2- (2-hydroxyethoxy) ethyl, 2- (2- (2-hydroxy Ethoxy) ethoxy) ethyl and the like. You may mix and use these.

  The first additive improves the interaction between the classified novolak resin and the alkaline developer that dissolves the classified novolak resin, so that the release film of the hydrophilic solvent easily penetrates between the photoresist pattern and the lower film. Like that. This is due to the interaction of the compatible functional group (for example, phenolic hydroxy group) of the classified novolak resin and the first additive by hydrogen bonding, and the pKa of the phenol hydroxy group that can be dissolved in the base of the classified novolak resin. This is because the base solubility of the classified novolak resin is increased. Thereby, the photoresist pattern manufactured by the photoresist composition is easily removed.

  When the first additive is less than 0.1% by weight based on the total weight of the photoresist composition, the interaction between the classified novolak resin and the alkali developer cannot be improved, and the photoresist pattern is removed. It is difficult to do. When the first additive exceeds 10% by weight, the heat resistance of the photoresist pattern decreases. Accordingly, it is desirable that the photoresist composition includes about 0.1 wt% to about 10 wt% of the first additive. More desirably, the photoresist composition includes about 0.1 wt% to about 5 wt% of the first additive.

(D) Second additive The second additive contains an acrylic copolymer represented by the following chemical formula (2).

  In the chemical formula (2), R 4, R 5 and R 6 each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R 7 is a carbon atom having 1 to 6 carbon atoms substituted or unsubstituted with a hydrogen valence. Represents hydrogen, R8 represents a substituted or unsubstituted benzyl group or phenyl group, m, n and k each independently represents a natural number of 1 to 99, and represents m + n + k = 100. For example, the alkyl group is methyl, ethyl, n-propyl, isopropyl, 1-butyl, 2-butyl, isobutyl, t-butyl, 1-pentyl, 2-pentyl, 3-pentyl, 1,1- or 2,2- Dimethylpropyl, 2-methylbutyl, 3-methylbutyl, 1-hexyl, 2-hexyl, 3-hexyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,2-dimethylbutyl 1,3-dimethylbutyl, 2,3-dimethylbutyl, 2-methylbutyl, 3-methylbutyl, n-octyl, 3-octyl, 1,1,3,3-tetramethylbutyl, n-decyl, cyclopentyl, 1 -Methylcyclopentyl, cyclohexyl, 2-methoxyethyl, 2-ethoxyethyl, 2-methoxypropyl, 2-ethoxypropy And the like. The substituted hydrocarbon is an alkyl group having 1 to 10 carbon atoms of a hydrocarbon, a hydroxyalkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or 3 to 6 carbon atoms. A cycloalkyl group having 3 to 6 carbon atoms and having at least one hydrogen substituted with a functional group such as a cycloalkyl group substituted with oxygen, nitrogen, silicon or the like is meant.

  The second additive prevents cracks on the surface of the photoresist pattern by minimizing the stress inside the photoresist pattern due to an etching solution having a high nitric acid content for etching the lower layer of the photoresist pattern. May be. The second additive may also prevent cracks from being easily generated on the surface of the photoresist pattern at a low temperature, for example, less than about 120 ° C., by using a classified novolac resin.

  The second additive may be produced by copolymerizing an unsaturated carboxylic acid and a radical polymerizable compound (for example, a comonomer). Examples of unsaturated carboxylic acids include methacrylic acid, acrylic acid, itaconic acid, and maleic acid. These may be used alone or in combination. Specific examples of the radical polymerizable compound include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, petyl (meth) acrylate, and benzyl (meth) acrylate. 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, and the like. These may be used alone or in combination.

  If the second additive is less than about 0.1% by weight of the total weight of the photoresist composition, cracks are easily formed in the photoresist pattern by external temperature and / or external chemicals. When the second additive exceeds about 10% by weight, the sensitivity characteristics of the photoresist composition are degraded. Accordingly, the second additive is desirably about 0.1 wt% or more and about 10 wt% or less of the total weight of the photoresist composition, and more desirably 0.5 wt% or more and about 9 wt% or less.

  When the weight average molecular weight of the second additive is less than about 5000 g / mol, the occurrence of cracks formed in the photoresist pattern cannot be prevented, and the weight average molecular weight of the second additive exceeds about 10,000 g / mol. In this case, the sensitivity characteristic of the photoresist composition is deteriorated. Therefore, the weight average molecular weight of the second additive is desirably about 5000 g / mol to about 10,000 g / mol, and more desirably 6000 g / mol to 9000 g / mol.

e) Organic solvents Examples of organic solvents include ethers, glycol ethers, ethylene glycol alkyl ether acetates, diethylene glycols, propylene glycol monoalkyl ethers, propylene glycol alkyl ether acetates, aromatic hydrocarbons, ketones And esters. These may be used alone or in combination. Specifically, examples of the organic solvent include ethyl lactate, 2-heptanone, cyclohexanone, anisole, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol methyl ether acetate (PGMEA), diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate. , Dipropylene glycol monomethyl ether, dipropylene glycol monomethyl acetate, butyl acetate, pentyl acetate, ethoxyethyl propionate and the like. These may be used alone or in combination.

f) Others In addition to the alkali-soluble resin, the dissolution inhibitor, the first and second additives, and the organic solvent, the photoresist composition may further include a surfactant, an adhesion enhancement system, and the like. The contents of the surfactant, the adhesion enhancement system, etc. may be determined in consideration of the contents of the alkali-soluble resin, the dissolution inhibitor, and the first and second additives. However, in order to prevent the content of the surfactant, adhesion promoting system, etc. from affecting the reaction of the dissolution inhibitor and the first and second additives, about 0% by weight or more of the total weight of the photoresist composition. It is desirable to consider 1% by weight or less.

  Surfactants can improve the applicability and phenomenon of the photoresist composition. Examples of surfactants include polyoxyethylene octyl phenyl ether, polyoxyethylene nonenyl phenyl ether, trade names, F171, F172, and F173 (Japan name). FC430, FC431 (Sumitomo 3M), trade name, KP341 (Shin-Etsu Chemical Co., Ltd.), and the like. These may be used alone or in combination.

  The adhesion promoter can improve the adhesion between the lower film and the photoresist pattern. Examples of the adhesion promoter include silane coupling agents having a reactive substituent such as a carboxyl group, a methacryl group, an isocyanate group, and an epoxy group. Specific examples of the silane coupling agent include: -methacryloxypropyltrimethoxysilane (vinyltriacetoxysilane), vinyltriacetoxysilane, vinyltrimethoxysilane silane (vinyltrimethoxysilane). -Isocyanatopropyltrioxysilane),-(3,4-epoxycyclohexylethyltrimethoxysilane) (beta-3,4-epoxy cyclohexylmethyltrimethylsilane) and the like. These may be used alone or in combination.

  The viscosity of the photoresist composition according to the embodiment of the present invention may be about 3 cP (centipoise) or more and about 15 cP or less. The photoresist composition may be patterned. In the pattern forming method using the photoresist composition according to the embodiment of the present invention, a photoresist film is formed on the substrate with the photoresist composition, and the photoresist film is, for example, UV, g-line, i -It may include exposing in a line or the like, developing the exposed photoresist film to form a patterned photoresist, and etching the substrate to form a pattern. The developer is desirably a water-soluble basic developer. By using a photoresist composition, it is possible to form a photoresist pattern that does not form cracks at a processing temperature of less than 120 ° C. or in the presence of an etchant.

  Hereinafter, the photoresist composition according to the embodiment of the present invention will be described in detail with reference to specific examples and comparative examples.

  (A-1) A first classified novolak resin having a weight average molecular weight of about 20000 g / mol obtained by reacting a phenol mixture obtained by mixing metacresol and paracresol in a weight ratio of about 60:40 with formaldehyde and then classifying it. About 12.0% by weight, (a-2) A phenol mixture prepared by mixing metacresol and paracresol in a weight ratio of about 50:50 was reacted with formaldehyde and then classified, and a weight average molecular weight obtained by classification was about 20000 g / mol. (B) 2,6-bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) -2,5-dimethylbenzyl] -4- Quinonediazide obtained by condensing methylphenol and 1,2-naphthoquinonediazide 5-phonyl chloride at a reaction mole ratio of about 1: 2.2 About 7% by weight of the compound, (c) 1,3-dihydrobenzene, about 0.5% by weight, (d) SPCY-series (product of Showa Polymer Co., Ltd.) having a weight average molecular weight of about 8000 g / mol Name) About 0.5% by weight of acrylic copolymer, (e) About 36.5% by weight of propylene glycol methyl ether acetate (PGMEA) as an organic solvent and about 35.5% by weight of ethyl lactate (EL) are mixed with fluorine. A photoresist composition having a viscosity of about 15 cP was produced by filtration through a resin filter. The glass transition points of the first and second classified novolak resins were about 120 ° C., respectively.

  (A-1) A first classified novolak resin having a weight average molecular weight of about 20000 g / mol obtained by reacting a phenol mixture obtained by mixing metacresol and paracresol in a weight ratio of about 60:40 with formaldehyde and then classifying it. About 12.0% by weight, (a-2) A phenol mixture prepared by mixing metacresol and paracresol in a weight ratio of about 50:50 was reacted with formaldehyde and then classified, and a weight average molecular weight obtained by classification was about 20000 g / mol. (B) 2,6-bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) -2,5-dimethylbenzyl] -4- Methyl penol and 1,2-naphthoquinonediazide-5-phonyl chloride (1,2-naphthoquinonedioxide-5 -Sulphonic acid chloride) condensed at a reaction mole ratio of about 1: 2.2, about 7% by weight of quinonediazide compound, (c) 1,2,3-trihydrobenzene pyrogallic acid (1,2,3-trihydrobenzene pyrogallic) acid) about 0.5% by weight, (d) SPCY-series (trade name) acrylic copolymer having a weight average molecular weight of about 8000 g / mol of Showa Polymer Co., Ltd., about 0.5% by weight, (e) propylene as an organic solvent A photoresist composition having a viscosity of about 15 cP was prepared by mixing with about 36.5% by weight of glycol methyl ether acetate (PGMEA) and about 35.5% by weight of ethyl lactate (EL) and filtering with a fluororesin filter. The glass transition points of the first and second classified novolak resins were about 120 ° C., respectively.

[Comparative Examples 1-6]
As shown in Table 1 below, photoresist compositions according to Comparative Examples 1 to 6 were manufactured.

  A-1: A phenol mixture in which metacresol and paracresol were mixed at a weight ratio of about 60:40 was reacted with formaldehyde, and then classified to obtain a weight average molecular weight of about 20000 g / mol, and a glass transition point of about 120 ° C. A first classified novolac resin.

  A-2: A phenol mixture in which metacresol and paracresol were mixed at a weight ratio of about 50:50 was reacted with formaldehyde, and then classified to obtain a weight average molecular weight of about 20000 g / mol, and a glass transition point of about 120 ° C. A second classified novolac resin.

  A-3: A phenol mixture obtained by mixing metacresol and paracresol in a weight ratio of about 60:40 was reacted with formaldehyde and then classified, and the weight average molecular weight obtained by classification was about 16000 g / mol, and the glass transition point was about 100 ° C. A third classified novolac resin.

  A-4: A phenol mixture prepared by mixing metacresol and paracresol in a weight ratio of about 50:50 was reacted with formaldehyde, and then classified to obtain a weight average molecular weight of about 15000 g / mol and a glass transition point of about 100 ° C. A fourth classified novolac resin.

  B: 2,6-bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) -2,5-dimethylbenzyl] -4-methylphenol and 1,2-naphthoquinonediazide-5-phonyl chloride A quinonediazide compound obtained by condensing a quinone with a reaction mole ratio of about 1: 2.2.

  C-1: 1,3-dihydrobenzene.

  C-2: 1,2,3-trihydrobenzene pyrogallolic acid.

  D-1: SPCY-series (trade name) acrylic copolymer having a weight average molecular weight of about 8000 g / mol from Showa Polymer Co., Ltd.

  D-2: SPCY-series (trade name) acrylic copolymer having a weight average molecular weight of about 20000 g / mol from Showa Polymer Co., Ltd.

  E: Propylene glycol methyl ether acetate (PGMEA).

  F: Ethyl lactate (EL).

Formation of photoresist pattern The photoresist compositions of Examples 1 and 2 and Comparative Examples 1 to 6 were each spin-coated on a silicon wafer treated with hexamethyldisilazane and heated at about 90 ° C. on a hot plate. A photoresist film of about 1.50 μm was formed by pre-baking for 60 seconds. The silicon wafer on which the photoresist film was formed was exposed using an NSR-2005 i9C I-line stepper (Nikon Corporation, NA = 0.57, = 0.60) while changing the exposure amount stepwise. Subsequently, the exposed photoresist film was heat-treated at about 110 ° C. for about 60 seconds, and then developed with about 2.38% tetramethylammonium hydroxide aqueous solution for about 60 seconds to form a photoresist pattern.

Characteristic Evaluation of Photoresist Pattern (1) Evaluation of Crack Resistance Each of the photoresist patterns formed using the photoresist compositions of Examples 1 and 2 and Comparative Examples 1 to 6 (trade name, Toyu Fine- After the addition of CHEM, Korea), the degree of soaking on the surface of the photoresist pattern was observed with a microscope, and the results were always good (◎), good (◯), normal (△) and bad ( The results are shown in Table 2 below.

(2) Strip property evaluation Each photoresist pattern formed using the photoresist compositions of Examples 1 and 2 and Comparative Examples 1 to 6 was removed using PRS-2000 (manufactured by Toyu Fine-Chem, Korea). Thereafter, the surface of the silicon wafer was observed, and the results are shown in Table 2 below as very good (◎), good (◯), normal (Δ), and bad (×).

(3) Evaluation of heat resistance After each of the photoresist patterns formed using the photoresist compositions of Examples 1 and 2 and Comparative Examples 1 to 6 was heat-treated at about 150 ° C. for about 150 seconds, a scanning electron microscope ( The profiles before and after the heat treatment using SEM) were compared, and the results are shown in Table 2 below as unchanged (◎), slightly changed (◯), normal (Δ), and very changed (×).

  Referring to Table 2, when Examples 1 and 2 are compared with Comparative Examples 1 to 6, it can be seen that crack resistance and strip properties are good. Further, according to Examples 1 and 2, it can be seen that by using a classified novolac resin having a glass transition point of about 120 ° C., the photoresist pattern is not deformed even at about 150 ° C.

Hereinafter, with reference to FIGS. 1-7, the manufacturing method of the display substrate which concerns on embodiment of this invention is demonstrated in detail.

  Referring to FIG. 1, a gate metal layer and a first photoresist pattern 210 are formed on a base substrate 110. The gate metal layer is patterned using the first photoresist pattern 210 as an anti-etching film to form a gate pattern including the gate line 121 and the gate electrode 123. The gate metal layer is formed of a double film structure including an aluminum layer and a molybdenum layer (not shown).

  Referring to FIG. 2, a gate insulating layer 130, a semiconductor layer 140a, an ohmic contact layer 140b, and a source metal layer 150 are sequentially formed on a base substrate 110 including a gate pattern. The source metal layer 150 is formed in a triple film structure including a first metal film M1 containing molybdenum, a second metal film M2 containing aluminum, and a third metal film M3 containing molybdenum.

  A second photoresist pattern 220 is formed on the base substrate 110 including the source metal layer 150. The second photoresist pattern 220 is formed on the base substrate 110 including the source metal layer 150 by about 10% by weight to about 25% by weight of an alkali-soluble resin and about 1% by weight to about 10% by weight of a dissolution inhibitor containing a quinonediazide compound. including. About 0.1 wt% or more and about 10 wt% or less of a first additive containing a benzoyl compound represented by the following chemical formula (1), about a second additive containing an acrylic copolymer represented by the following chemical formula (2) A photoresist film containing a positive photoresist composition containing not less than 1% by weight and not more than 10% by weight and an organic solvent is formed, and the photoresist film is exposed using the mask 300 and then developed. Good.

  In the chemical formula (1), R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkylhydroxy group having 1 to 10 carbon atoms, and R1, R2, and At least one of R3 represents a hydroxy group, and in the chemical formula (2), R4, R5 and R6 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R7 represents a hydrogen valence substitution or R represents an unsubstituted hydrocarbon having 1 to 6 carbon atoms, R8 represents a benzyl group or a phenyl group, m, n and k each independently represent a natural number of 1 to 99, and m + n + k = 100. The substituted hydrocarbon means a functional group such as a hydrogen valence alkyl group, a hydroxyalkyl group, an alkoxy group or a cycloalkyl group having 3 to 6 carbon atoms of the unsubstituted hydrocarbon.

  As shown in FIG. 2, the mask 300 includes a light shielding part 310 that blocks light, a semi-transparent part 320 that transmits only part of the light, and a transparent part 330 that transmits light. The photoresist film corresponding to the light shielding portion 310 is not removed by the developer and remains on the source metal layer 150 with the first thickness d1. The first thickness d1 may be substantially the same as the initial thickness of the photoresist film. A part of the photoresist film corresponding to the semi-translucent portion 320 is removed by the developer, and a part remains. As a result, the photoresist film remains in the region corresponding to the semi-transparent portion 320 with the second thickness d2. The second thickness d2 is thinner than the first thickness d1. The photoresist film corresponding to the light transmitting portion 330 is removed by the developer. Accordingly, the photoresist film is patterned to form the second photoresist pattern 220 including the first thickness portion TH1 having the first thickness d1 and the second thickness portion TH2 having the second thickness d2. Form. The first thickness portion TH1 is formed in a region where a source pattern is formed in a subsequent process. Since the photoresist composition has good photosensitivity, the first thickness portion TH1 and the second thickness portion TH2 having a fine size may be formed in a stable form.

  After forming the second photoresist pattern 220, the base substrate 110 including the second photoresist pattern 220 may be heat treated. The adhesion between the second photoresist pattern 220 and the source metal layer 150 is improved by the heat treatment. The heat treatment process is performed at a temperature of about 140 ° C. or higher and about 150 ° C. or lower. The second photoresist pattern 220 formed of the photoresist composition is not modified even after the heat treatment process. In addition, even if the second photoresist pattern 220 formed of the photoresist composition is subjected to a heat treatment step, the sidewall of the second photoresist pattern 220 has an inclination angle (θ) with respect to the surface of the base substrate 110 as a heat treatment step. There is virtually no change before and after. The change in the inclination angle (θ) may be about 0 ° or more and about 15 ° or less, and preferably about 5 ° or more and about 10 ° or less. Accordingly, the shape of the second photoresist pattern 220 before the heat treatment step may be substantially the same as the shape of the second photoresist pattern 220 after the heat treatment step.

  As shown in FIG. 3, the source metal layer 150 is etched with the second photoresist pattern 220 using an etching prevention film, and then the ohmic contact layer 140b and the semiconductor layer 140a are etched. For example, the source metal layer 150 may etch the first, second, and third metal films M1, M2, and M3 simultaneously. Etching may be performed using an integrated etching solution. The integrated etchant may contain nitric acid. Even if the 2nd photoresist pattern 220 formed with the photoresist composition used integrated etching liquid, the crack does not generate | occur | produce on the surface. In addition, the sidewall surface of the second photoresist pattern 220 may be substantially the same as the etched surface of the source metal layer 150.

   3 to 7, the source metal layer 150 having a triple film structure is shown as a single layer for convenience.

  Referring to FIG. 3, the source metal layer 150 is patterned to form a data line 152 and a spare electrode pattern 154 connected to the data line 152 on the base substrate 110. The data line 152 intersects with the gate line 121, and the spare electrode pattern 154 overlaps the gate electrode 123 on the gate electrode 123.

  Subsequently, the ohmic contact layer 140b and the semiconductor layer 140a are etched using the data line 152, the spare electrode pattern 154, and the second photoresist pattern 220 as an etching prevention film. As a result, a preliminary active pattern 142 is formed below the preliminary electrode pattern 154, and a line pattern (not shown) is formed below the data line 152. The preliminary active pattern 142 includes a semiconductor pattern 142a and an ohmic contact pattern 142b.

  Referring to FIG. 4, the second thickness portion TH2 of the second photoresist pattern 220 is removed to form a residual pattern 222. By removing the second photoresist pattern 220 by the second thickness d2, the second thickness portion TH2 is removed, and the first thickness portion TH1 remains by the third thickness d3. A residual pattern 222 is formed. A portion of the preliminary electrode pattern 154 is exposed through the residual pattern 222.

  Referring to FIG. 5, the residual pattern 222 is used as an anti-etching film to remove a part of the preliminary electrode pattern 154, and the source electrode 156 connected to the data line 152 and the drain electrode 158 spaced apart from the source electrode 156. Form. As a result, a source pattern including the data line 152, the source electrode 154 and the drain electrode 156 is formed on the base substrate 110.

  The preliminary electrode pattern 154 may be patterned using an integrated etching solution. The residual pattern 222 formed using the photoresist composition is hardly subjected to internal or external stress by the integrated etching solution. As a result, no cracks are generated on the surface of the residual pattern 222.

  Subsequently, the ohmic contact pattern 142b of the preliminary active pattern 142 exposed between the source electrode 156 and the drain electrode 158 is removed using the source electrode 156 and the drain electrode 158 as an etching prevention film. As a result, an active pattern 146 in which a part of the semiconductor pattern 142a is exposed between the source electrode 156 and the drain electrode 158 is formed.

  Although the residual pattern 222 has undergone the steps described with reference to FIG. 4 and FIG. Therefore, the etching surface of the source electrode 156 and the drain electrode 158 may be substantially the same as the etching surface of the active pattern 146, as in the portion indicated by “SP” in FIG. That is, the active pattern 146 may not protrude relative to the source electrode 156 and the drain electrode 158. Further, the etched surfaces of the data line 152 and the line pattern 144 may be substantially the same.

  Referring to FIG. 6, the residual pattern 222 is removed using a strip solution. The residual pattern 222 can be easily removed while having high heat resistance, and the reliability of the source pattern formation process can be improved.

  On the base substrate 110 having the gate electrode 123, the active pattern 146 including the channel portion CH between the source electrode 156 and the drain electrode 158, and the thin film transistor SW including the source electrode 156 and the drain electrode 158, the passivation layer 160 and the flat surface are continuously formed. The formation layer 170 is formed.

  Referring to FIG. 7, the passivation layer 160 and the planarization layer 170 are patterned to form a contact hole CNT that exposes one end of the drain electrode 158. The planarization layer 170 may be omitted.

  Subsequently, an electrode layer is formed on the base substrate 110 in which the contact holes CNT are formed, and the pixel layer 180 is formed by patterning the electrode layer. The pixel electrode 180 contacts the drain electrode 158 through the contact hole CNT and is electrically connected to the thin film transistor SW.

  In the embodiment of the present invention, the step of forming the contact hole CNT and the step of patterning the electrode layer have been described as separate steps. However, the contact hole CNT and the electrode layer may be patterned using one mask.

  According to the embodiment of the present invention, the photoresist pattern can be easily removed while improving the heat resistance, and the occurrence of cracks in the photoresist pattern can be minimized. Further, in the method for manufacturing a thin film transistor including a step of forming an active pattern and a source pattern using one mask, it is possible to prevent the active pattern from protruding compared to the source pattern.

  As mentioned above, although the suitable Example of this invention was described in detail, referring an accompanying drawing, this invention is not limited to this example. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes and modifications within the scope of the technical idea described in the claims. These are naturally understood to belong to the technical scope of the present invention.

110 Base substrate 121 Gate line 123 Gate electrode 130 Gate insulating layer 140a Semiconductor layer 140b Ohmic contact layer 146 Active pattern 150 Source metal layer M1, M2, M3 First, second, third metal film 152 Data line 154 Preliminary electrode pattern 156 Source electrode 158 Drain electrode 160 Passivation layer 170 Planarization layer 180 Pixel electrodes 210 and 220 First and second photoresist patterns 222 Residual pattern

Claims (10)

An alkali-soluble resin;
A dissolution inhibitor containing a quinonediazide compound;
A first additive containing a benzole compound represented by the following chemical formula (1);
A second additive containing an acrylic copolymer represented by the following chemical formula (2);
An organic solvent,
A photoresist composition comprising:


(In the chemical formula (1), R1, R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an alkylhydroxy group having 1 to 10 carbon atoms, R1, At least one of R2 and R3 represents a hydroxy group, and in the chemical formula (2), R4, R5, and R6 each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R7 represents hydrogen. A valence-substituted or unsubstituted hydrocarbon having 1 to 6 carbon atoms, R8 represents a benzyl group or a phenyl group, m, n and k are each independently a natural number of 1 to 99, and m + n + k = 100). The alkali-soluble resin is
The photoresist composition according to claim 1, comprising a classification type novolac resin.   3. The photoresist composition according to claim 2, wherein the classified type novolac resin has a glass transition point of 120 ° C. or higher and 150 ° C. or lower.   3. The photoresist composition according to claim 2, wherein the classified type novolak resin has a weight average molecular weight of 20000 g / mol to 30000 g / mol. The dissolution inhibitor is
2. The photoresist composition according to claim 1, which is an ester compound obtained by reacting a phenolic compound having at least one hydroxy group with a quinonesulfonic acid halogen compound.   2. The photoresist composition according to claim 1, wherein the second additive has a weight average molecular weight of 5000 g / mol or more and 10,000 g / mol or less. The second additive is
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, petyl (meth) acrylate, benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxytri At least one selected from the group consisting of ethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, and penoxypolyethylene glycol (meth) acrylate is copolymerized with an unsaturated carboxylic acid. The photoresist composition according to claim 1, wherein The alkali-soluble resin is
A first classified novolak resin using a phenol mixture in which metacresol and paracresol are mixed at a weight ratio of 60:40;
And a second classified novolac resin using a phenol mixture in which metacresol and paracresol are mixed at a weight ratio of 50:50.   10% by weight to 25% by weight of the alkali-soluble resin, 1% by weight to 10% by weight of the dissolution inhibitor, 0.1% by weight to 10% by weight of the first additive, 0.1% by weight 2. The photoresist composition according to claim 1, comprising 10 wt% or less of the second additive and an organic solvent. Forming a gate pattern including a gate line and a gate electrode on the base substrate;
Forming a gate insulating layer, a semiconductor layer, an ohmic contact layer and a source metal layer on the base substrate including the gate pattern;
On the base substrate including the source metal layer, an alkali-soluble resin, a dissolution inhibitor including a quinonediazide compound, a first additive including a benzol compound represented by the following chemical formula (1), and the following chemical formula (2): Forming a photoresist pattern using a photoresist composition comprising a second additive comprising an acrylic copolymer and an organic solvent,
Patterning the source metal layer using the photoresist pattern as an etching prevention film to form a source pattern including a data line, a source electrode and a drain electrode, and an active pattern formed under the source electrode and the drain electrode;
A method of manufacturing a display substrate, comprising: forming a pixel electrode electrically connected to the drain electrode on the base substrate including the source pattern and the active pattern.


(In the chemical formula (1), R1, R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an alkylhydroxy group having 1 to 10 carbon atoms; , R2 and R3 each represents a hydroxy group, and in the chemical formula (2), R4, R5 and R6 each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R7 represents a hydrogen atom. A valence-substituted or unsubstituted hydrocarbon having 1 to 6 carbon atoms, R8 represents a benzyl group or a phenyl group, m, n and k are each independently a natural number of 1 to 99, and m + n + k = 100).